Wednesday, June 7, 2017

Consuming low-fat dairy increases the risk of Parkinson's disease

Consuming at least three servings of low-fat dairy a
day is associated with a greater risk of developing Parkinson's disease
compared to consuming less than one serving a day, according to a large
study published in the June 7, 2017, online issue of Neurology®,
the medical journal of the American Academy of Neurology. In addition,
drinking more than one serving of low-fat or skim milk per day is
associated with a greater risk of developing Parkinson's disease
compared to drinking less than one serving per week. The study results
do not show that dairy products cause Parkinson's disease--they just
show an association.

"Our study is the largest analysis of dairy and Parkinson's to
date," said Katherine C. Hughes, ScD, of the Harvard T.H. Chan School of
Public Health in Boston. "The results provide evidence of a modest
increased risk of Parkinson's with greater consumption of low-fat dairy
products. Such dairy products, which are widely consumed, could
potentially be a modifiable risk factor for the disease."

For the study, researchers analyzed approximately 25 years of data
on 80,736 women enrolled in the Nurses' Health Study and 48,610 men
enrolled in the Health Professionals' Follow-up Study.

Participants in
these studies completed health questionnaires every two years and diet
questionnaires every four years. During that time, 1,036 people
developed Parkinson's.

Researchers examined what kinds of dairy each person consumed,
including milk, cream, cheese, yogurt, ice cream, butter, margarine and
sherbet. They then looked at whether full-fat dairy, as whole milk, was
associated with a risk of Parkinson's disease; there was no association.
However, those who consumed at least three servings of low-fat dairy a
day had a 34 percent greater chance of developing Parkinson's than
people who consumed less than one serving per day.

The researchers also
found that when looking specifically at skim and low-fat milk
consumption, there was a 39 percent greater chance of developing
Parkinson's for people who consumed more than one serving per day
compared to those who consumed less than one serving per week. Eating
sherbet or frozen yogurt also was linked to a modest increased risk.

In a meta-analysis, looking at a group of studies, the researchers
found that total dairy intake was associated with an increased risk of
Parkinson's disease.

The overall conclusions from these studies was that frequent
consumption of dairy products was associated with a modest increased
risk of Parkinson's disease.

It is important to note that the risk of developing Parkinson's was
still very low. Of the 5,830 people who consumed at least three servings
per day of low-fat dairy at the start of the study, only 60 people, or 1
percent, developed the disease over the study period. In comparison, of
the 77,864 people who consumed less than one serving per day of low-fat
dairy, 483 people, or 0.6 percent, developed Parkinson's.